NEW ORLEANS -- Hispanics who immigrate to the U.S. may be less likely to suffer a stroke than whites, researchers found.

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This study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

This study found that foreign-born Hispanics had a decreased risk of first stroke compared to both non-Hispanic whites and Hispanics born in the U.S., whose stroke risks were comparable when adjusted for socioeconomic factors.

Note for this study 15,784 patients without stroke, whose mean age was 66 in 1998, were followed through 2008 for stroke events.

NEW ORLEANS -- Hispanics who immigrate to the U.S. may be less likely to suffer a first stroke compared with whites or even U.S.-born Hispanics, researchers found.

Foreign-born Hispanics who came to the U.S. after age 6 had a 42% lower risk of first stroke incidence compared with non-Hispanic whites living here, according to J. Robin Moon, DPH, and Maria Glymour, PhD, of Harvard University in Boston.

The benefits, however, aren't conveyed to Hispanics born in the states. After controlling for socioeconomic factors, this group had about the same first stroke incidence as whites, Moon and Glymour found.

Their work will be presented at the American Academy of Neurology meeting here in April.

"Whatever the reason for this health advantage among Hispanics, it is thought that it dissipates among U.S.-born Hispanics," Moon told MedPage Today. "Some adverse aspect of life in the U.S. may compromise their health and increase the risk of stroke."

Moon and Glymour assessed longitudinal data from 15,784 patients in the Health and Retirement Study, all of whom were free of stroke at baseline in 1998. The group's mean age was 66.

A total of 14,360 were non-Hispanic white and the other 1,424 were Hispanic, determined to be foreign-born if they came to the U.S. after age 6.

Through the end of follow up in 2008, there were a total of 1,388 stroke events.

They found that in analyses adjusted for socioeconomic factors, Hispanics born abroad had a lower risk of stroke than whites living in the states all their lives (OR 0.58, 95% CI 0.42 to 0.82).

And while Hispanics born in the U.S. had a higher risk of stroke incidence than whites in initial analyses (OR 1.44, 95% CI 1.08 to 1.90), the relationship disappeared in models adjusted for socioeconomics.

Moon said there are a number of likely explanations for the findings. Immigrants may be more likely to carry healthier habits with them, or selection bias may be at play, with healthier patients undertaking the challenges of immigration in the first place, she said.

Another hypothesis potentially supported by the current findings, Moon said, is that any protective cultural buffering likely diminishes over time with acculturation, hence the lack of benefit seen among Hispanics born in the U.S.

Moon said the next step is to look at which factors contribute to that protective benefit. For instance, does the age of arrival in the U.S. more heavily influence health outcomes, or does the duration of the stay have a greater impact?, she said.

"We're not able to conclusively make any statement about whether it's the amount of time or the timing," Moon said, "but the evidence suggests that it's likely both."

A recent study in the Journal of Health and Social Behavior, however, offered contrary information to these findings. That research found that immigrants are less likely to use the U.S. healthcare system when they first come to the states and run the risk of missing out on treatment for conditions such as high blood pressure, which puts them at greater risk of cardiovascular disease.

Study author Jen'nan Read, PhD, of Duke University, told MedPage Today that stroke may be a different animal, as its etiology is still being disentangled.

Still, she said the "healthy migrant" hypothesis is based on an incomplete picture because these patients are generally not noticed in the healthcare system until they experience larger health problems.

"Immigrants may be healthier when they get here, but the degree to which they're healthier isn't clear because they don't go to the doctor when they first get here," Read said. "Our assumption is that they're healthy because they don't report bad health."

"But if our question is, has the doctor told you you're not healthy, then you might report bad health," she added, warning that survey methodology may not be asking the right questions to determine migrant health status.

Introducing migrants to the U.S. healthcare system earlier after their arrival may lower the risk of severe outcomes down the road, and help paint a more accurate picture of migrant health, Read said.